Measurement of the masses and lifetimes of the charmed mesonsD ⁰,D ⁺ andD ⁺_s

Abstract

We present the final results on the measurement of the masses and lifetimes of the mesonsD ⁰,D ⁺ andD ⁺_s in the NA32 experiment at the CERN SPS, using silicon microstrip detectors and charge-coupled devices for vertex reconstruction. We measure the following lifetimes:$\tau _{D^0 } = 3.88 \pm _{0.21}^{0.23} \cdot 10^{ - 13} s$ using a sample of 479D°→K ⁻π⁺π⁻π⁺ and 162D°→K ⁻π⁺ decays;$\tau _{D^ + } = 10.5 \pm _{0.72}^{0.77} \cdot 10^{ - 13} s$ with a sample of 317D ⁺→K ⁻π⁺π⁺ decays;$\tau _{D_s^ + } = 4.69 \pm _{0.86}^{1.02} \cdot 10^{ - 13} s$ with a sample of 54D ⁺_s →K ⁺ K ⁻π⁺ decays. We measure the following masses:m _D ⁰=1864.6±0.3±1.0 MeV,m _D ⁺=1870.0±0.5±1.0 MeV and$m_{D_s^ + }$=1967.0±1.0±1.0 MeV.